Cross-Carrier Scheduling With Dynamic USS Switching Between Cells
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Solution Overview
Problem
In 5G mobile communication, efficient switching between user-specific search spaces (USSs) on bandwidth parts (BWPs) of different cells is challenging due to limitations in cross-carrier scheduling, where only one cell can have an effective USS at a specific time point, leading to inefficiencies in control channel payload management.
Innovation Solution
A cross-carrier scheduling method that involves a terminal device and an access network device to monitor and switch between USSs on BWPs of two cells based on indication information, including deactivation, activation, and BWP switching, using RRC signaling, MAC-CE, or DCI to optimize the switching process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If cross-carrier scheduling is implemented with USS on multiple cells, then scheduling flexibility is improved, but control channel payload complexity increases
Solution Approach 1:
The patent implements dynamic switching between USS on first cell and USS on second cell based on reception quality conditions. The terminal device monitors reference signals and switches search spaces dynamically, allowing the system to adapt to changing channel conditions while maintaining manageable control channel complexity through conditional activation rather than simultaneous operation of all search spaces.
Solution Approach 2:
The patent changes the parameter of search space configuration based on reception quality. When quality exceeds a threshold, the system switches from monitoring USS on the first cell to USS on the second cell. This parameter-based switching allows flexible adaptation without permanently increasing control channel payload complexity, as only one USS is actively monitored at a time based on current conditions.
2Productivity
If USS switching between cells is implemented, then transmission efficiency is improved, but switching complexity increases
Solution Approach 1:
The patent configures multiple USS in advance on different cells, but only activates them based on pre-defined reception quality thresholds. This preliminary configuration allows rapid switching without complex real-time decision-making, as the conditions for switching are predetermined. The terminal device simply compares current quality measurements against stored thresholds to determine when to switch search spaces.
Solution Approach 2:
The patent implements a feedback mechanism where the terminal device continuously monitors reference signal quality and uses this feedback to determine when to switch between USS on different cells. The quality measurement feedback triggers switching decisions, creating a closed-loop system that improves transmission efficiency while keeping switching logic simple through clear threshold-based triggers rather than complex optimization algorithms.
Data Source
AI summary
Embodiments of this application provide cross-carrier scheduling methods, terminal devices, access network devices, and chips. In an example method, the terminal device receives first indication information when monitoring, in at least one user equipment (UE)-specific search space (USS) in a first cell, a physical downlink control channel (PDCCH) for scheduling data of a third cell. The terminal device stops, based on the first indication information, monitoring, in the at least one USS in the first cell, the PDCCH for scheduling the data of the third cell, and determines to monitor, in at least one USS in a second cell, a PDCCH for scheduling the data of the third cell, to implement switching between USSs in two cells.